DESCRIPTION: (Applicant's Abstract) This proposal is a response to RFA 00-004, "The Next Generation of Drug Abuse Prevention Research." We propose to examine the relative importance of the two theoretical content components of the school-based Project Towards No Drug Abuse (TND) curricula in effecting drug abuse prevention effects on tobacco, alcohol, marijuana and hard drug use (cognitive perception versus behavioral skills, versus their combination). Project TND is an empirically validated indicated drug abuse prevention program, which has shown positive one-year outcomes over three experimental replication trials. Instruction will be provided by both experienced project staff health educators and school teachers recently trained in the program as a means of examining implementer characteristics. The impact of the program content and implementer characteristics will be examined in two cohorts of youth varying in contextually defined risk, in a randomized experimental design. Project and school staff-delivered classroom programs will be implemented in 12 high schools and compared to 4 standard care (control) condition schools, in a seven-condition randomized design replicated across two school contexts (traditional and alternative high schools, 32 schools total). We will assess student drug use behavior at baseline (pretest), post program (immediate post-test), and 1-year follow-up. We will apply a series of sophisticated models to analyze the collected data for potential experimental, mediational and moderational effects as specified by hypotheses generated from the underlying theoretical base.